Trimming square set

ABSTRACT

Disclosed herein is a trimming square set suitable for trimming photographic films, drawings or the like into arbitrary rectangular shapes. 
     The square set utilized the rule that the four apices of a rectangle are invariably located on one circumference, permitting to form a rectangle of a desired size in an extremely facilitated manner by means of a first square member rotatably mounted on a base plate, a second square member rotatably mounted on a slide plate which is slidable on the base plate, and a circular hole provided in the base plate. Similar rectangles of different sizes can be formed easily by sliding the slide plate on the base plate.

FIELD OF THE INVENTION

This invention relates to a square set particularly suitable fortrimming photographic films, drawing sheets or the like into arectangular shape.

BACKGROUND OF THE INVENTION

Compilation of materials for catalogues, books, newspapers or the likeinvariably involves trimming jobs, for example, trimming of an image ona photographic film or drawing to be fitted in a specified space orframe on a catalogue or the like. In such a case, it has been the usualpractice to trim the object image into a square or rectangular shapeconforming with the shape of the mounting space. This job is verytroublesome and time-taking and requires meticulous skill. Therefore,there have been demands for development of a drafting or drawingimplement which can facilitate the trimming jobs.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a trimming squareset which can form a desired rectangular shape in a simple and quickmanner by the use of a couple of square members.

It is another object of the invention to provide a trimming square setwhich permits trimming of rectangular shapes of arbitrarylength-to-width ratios quickly in a facilitated manner.

It is a further object of the invention to provide a trimming square setwhich permits trimming of rectangular shapes of arbitrary areal ratiosquickly in a facilitated manner.

The trimming square set according to the invention basically comprises:a base plate having a circular opening therein; a first square memberhaving inner edges set at right angles to each other and pivotallysupported on the base plate by a pin member located at a positionproximate to the peripheral edge of the circular opening, at a pointproximate to an intersecting point of the inner edges; a slide platebeing slidingly movable on said base plate in a direction parallel withan imaginary line passing through the center of the pin member and thecircular opening and provided with a semi-circular notch on the innerside thereof congruently with the shape of the peripheral edge of thecircular opening of said base plate; and a second square member havinginner edges set at right angles to each other and pivotally supported onthe slide plate on said base plate by a second pin member located on theimaginary line and in a position proximate to the peripheral edge of thesemi-circular notch, at a point proximate to the intersecting point ofthe inner edges thereof.

With the above-described arrangement, utilizing the rule that the fourapeces of a rectangle are located on one and same circumference, arectangle is formed in an extremely simple manner by setting thesemi-circular notch of the slide plate congruently on the circularopening of the base plate and positioning the inner edges of one squaremember on a point of intersection of the inner edges of the other squaremember with the marginal edge of the circular opening of the base plate.In addition, after forming a rectangle in this manner, similarrectangular shapes of arbitrary sizes can be formed simply by slidingthe slide plate.

Further, the trimming square set according to the invention is providedwith a scale of length-to-width ratio along the peripheral edge of thecircular opening of the base plate or of the semi-circular notch of theslide plate which is shaped congruently with the circular opening, sothat a rectangle of a desired length-to-width ratio can be obtainedsimply by aligning the semicircular notch of the slide plate with thecircular opening in the base plate and positioning the inner edges ofone square member on the graduations of the desired length-to-widthratio. This is especially convenient when trimming a photograph ordrawing into a rectangular shape of a given length-to-width ratio.

Moreover, the trimming square set according to the invention is providedwith a scale of areal reduction ratio on part of frames provided aroundthe outer periphery of the base plate, indicating the areal reductionratios of the rectangular shape which is formed by the inner edges ofthe first and second square members, thereby permitting to form arectangle of a desired reduction ratio easily.

The above and other objects, features and advantages of the inventionwill become apparent from the following description and the appendedclaims, taken in conjunction with the accompanying drawings which showby way of example preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a perspective view of a trimming square set embodying thepresent invention;

FIG. 2 is an exploded perspective view of the same trimming square set;

FIGS. 3A, 3B, 4A, and 4B are plan views of the trimming square set inuse, showing at A the trimming square forming a rectangular shape of agiven length-to-width ratio and at B the trimming square forming asimilar rectangular shape on a reduced scale; and

FIGS. 5A and 5B are diagrammatic illustrations employed to explain howto use the trimming square set.

THE BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIGS. 1 and 2, the trimming square set according to theinvention includes a rectangular base plate 11 of a transparentsynthetic resin, which is centrally provided with a circular opening 12and an outer frame 13 with rectangular inner edges around the circularopening 12. The longer sides 13a, 13a of the frame 13 are provided withgrooves 14.

A first square member 15a of a transparent synthetic resin isconstituted by arms 16a, 16a with inner edges thereof set at rightangles to each other, and rotatably mounted on the base plate 11 by apin 20a which is inserted in a pin hole 18a provided at as close aposition as possible to an intersecting point 17a of the inner edges ofthe square arms 16a, 16a and a pin hole 19a provided in the base plate11 at as close a position as possible to the peripheral edge of thecircular opening 12. The base plate 11 is also provided with a screwhole 21a at a position proximate to the pin hole 19a for receiving ascrew 22a thereinto, while the first square member 15a is provided withan arcuate slot 23a on the outer side of and about the pin hole 18awhich is located at the center of the arc of the slot 23a. By tighteninga box nut 24a onto the screw 22a which is received in the hole 21a ofthe base plate 11 and the arcuate slot 23a, the first square 15a isfixed at an arbitrary angle on the base plate 11.

Thus, even if the first square member 15a is turned relative to the baseplate 11, the intersecting point 17a of the inner edges of its arms 16a,16a is invariably located substantially at one set point at theperipheral edge of the circular opening 12 of the base plate 11.

A slide plate 25 which is likewise formed of a transparent syntheticresin material has its opposite ends fitted in the grooves 14 providedin the longer sides 13a of the frame 13 along the inner edges thereof,and is provided with a semi-circular notch 26 on the inner side, whichsemi-circular notch 26 congruently overlies on the circular opening 12of the base plate 11 when the slide plate 11 is abutted on one of theshorter end frame portions 13b (the one located away from the firstsquare member 15a) of the outer frame 13. The slide plate 25 is slidablein the grooves 14 in a direction parallel with an imaginary line passingthrough the centers of the pin 20a and the circular opening 12.

A second square member 15b similarly formed of a transparent syntheticresin material is constituted by arms 16b, 16b with inner edges thereofset at right angles to each other, and rotatably mounted on the slideplate 25 by a pin 20b which is fitted in a pin hole 18b provided in thesecond square member 15b at as close a position as possible to a pointof intersection 17b of the inner edges of the arms 16b, 16b and a pinhole 19b provided in the slide plate 25 at a position provided as closea position as possible to the peripheral edge of the semi-circularnotch. The pin 20b is located on an imaginary line passing through thecenters of the pin 20a and the circular opening 12. Accordingly, thedistance between the pins 20a and 20b is substantially equal to thediameter of the circular opening 12.

Similarly to the first square member 15a, the second square member 15bis fixable at an arbitrary angle on the slide plate 25 by tightening abox nut 24b onto a screw 22b which is fitted in a hole 21b provided inthe slide plate 25 at a position close to the aforementioned pin hole19b and the arcuate slot 23b in the second square member 15b.

Therefore, in the same manner as the first square member 15a, theintersecting point 17b of the inner edges of the arms 16b, 16b isconstantly located substantially on one point on the peripheral edge ofthe semi-circular notch 26 of the slide plate 25 even if rotatedrelative to the slide plate 25.

A scale 27 of length-to-width ratio provided along the peripheral edgeof the circular opening, on the side away from the slide plate 25,indicates the length-to-width ratio of the rectangle formed by the firstand second square members 15a and 15b, each graduation of the scalebearing a figure of the length-to-width ratio of the correspondingrectangle, for example, a figure of "2" indicating that thelength-to-width ratio is 1:2. If desired, the scale 27 oflength-to-width ratio may be provide along the peripheral edge of thenotch 26 of the slide plate 25.

Denoted at 28 is a reduction scale which is provided on the frameportion 13a, the graduations of the scale bearing figures which indicatereduction ratios of the rectangular area formed by the arms 16a, 16a and16b, 16b of the first and second squares 15a and 15b, for example,figures of 1/2 indicating that the reduction ratio of the rectangulararea is 1/2. The reference numeral 29 indicates scales on the squarearms 16a, 16a and 16b, 16b having zero points at the intersecting points17a and 17b respectively.

For trimming an image on a photographic film to fit same in a specifiedframe on a layout sheet, the above-described trimming square is handledin the manner as follows.

For example, the trimming operation is explained by way of a case wherean image 41 on a photographic film 40 as shown in FIG. 5A is trimmedinto the shape of a frame 42 on a layout board 43 as shown in FIG. 5B.In such a case, an opaque paper sheet may be releasably adhered to thephotographic film 40 beforehand.

In the first place, after loosening the box nuts 24a and 24b, theintersecting point 17a of the first square member 15a is positioned onthe point P of the frame 42, and the intersecting point 17b of thesecond square member 15b is positioned on the diagonal line 42a of theframe 42. Nextly, the first square member 15a is turned until the inneredges of its arms 16a, 16a get in line with the end and side lines 42band 42c of the frame 42, and in this state the first square member 15ais fixed to the base plate 11 by tightening the box nut 24a. Then, thesquare is detached from the layout frame 42, and the slide plate 25 ismoved until it abuts against the end frame 13b on the left side. In thisstate, the second square member 15b is turned to position which its arms16b, 16b is positioned on the intersecting points of the inner edges ofarms 16a, 16a of the first square member 15a with the marginal edge ofthe circular opening 12 in the base plate 11, and fixed to the slideplate 25 by tightening the box nut 24b. In this way, the square arms areset in position.

The inner edges of the square arms 16a, 16a and 16b, 16b thus form arectangle 30 as the distance between the pins 20a and 20b at the centersof rotation of the first and second square members 15a and 15b issubstantially equal to the diameter of the circular opening 12 in thebase plate 11 and an imaginary line which connects the pins 20a and 20bpasses through the center of the circular opening 12. Further, as shownin FIGS. 3B and 4B, a rectangle 30a similar to the thus obtainedrectangle 30 is formed by sliding the slide plate 25 of the secondsquare member 15b along the grooves 14 from that position.

The square arms which are set to form a rectangle 30a similar to thelayout frame 42 in this manner is placed on the photographic film 40 tobe trimmed, and, after framing in necessary portions by sliding theslide plate 25, trimming lines are drawn on the film or an overlyingopaque paper sheet with a pencil or other suitable means.

Following are procedures for trimming a photographic film into arectangular shape of a desired length-to-width ratio or areal reductionratio.

Firstly, as shown in FIGS. 3A and 4A, the slide plate 25 is abuttedagainst the left end frame 13b of the frame 13, congruently overlayingthe semi-circular notch 26 of the slide plate 25 on the circular opening12 of the base plate 11. In this state, the inner edge of one arm 16b ofthe second square member 15b is positioned at a desired length-to-widthratio on the scale 27 and then the second square member 15b is fixed tothe slide plate 25 by tightening the box nut 24b. Thereafter, the firstsquare member 15a is turned until the inner edge of its one square arm16a is positioned at the point of intersection of the inner edge of thesquare arm 16b and the marginal edge of the circular opening 12 of thebase plate 11, fixing the first square member 15a to the base plate 11by tightening the box nut 24a.

Thus, the inner edges of the square arms 16a, 16a and 16b, 16b define arectangle 30, since the distance between the pins 20a and 20b at thecenters of rotation of the two square members 15a and 15b issubstantially equal to the diameter of the circular opening 12 on thebase plate 11 and an imaginary line which connects the pins 20a and 20bpasses through the center of the opening 12. The rectangle 30 thusformed has a length-to-width ratio of the value indicated by thegraduation on the scale 27, on which the inner edges of the arms 16b ofthe second square member 15b register.

Further, as illustrated in FIGS. 3B and 4B, if the slide plate 25 of thesecond square member 15b is slided from the that position along thegrooves 14, the inner edges of the square arms form a rectangle 30bsimilar to the above described rectangle 30.

If, for example, the end face of the slide plate opposite to the endframe portion 13b registers on a graduation of 1/2 as a resulting ofsuch a sliding shift of the side plate 25, the resulting rectangle 30ahas an area which is 1/2 of the area of the original rectangle 30.

The square which are set to form a rectangle of desired length-to-widthratio and size in this manner are placed on a photographic film to betrimmed, and then the slide plate 25 is moved and set in a position of adesired frame size, tracing the frame line on the photographic film orthe overlying opaque paper sheet if necessary.

The length-to-width ratio of the rectangle 30 can be changed arbitrarilyby selecting a suitable value on the scale 27 in consideration of thesize of an image on the photographic film to be trimmed. When alength-to-width ratio of 1:2 is selected, it becomes possible to formrectangles corresponding to the length-to-width ratio of paper sheets ofJIS A- and B-series.

The arms 16a, 16a and 16b, 16b of the first and second square members15a and 15b may be arranged either in the manner as shown in FIG. 1where arms of the second square member are laid on the arms of the othersquare member, or in the manner as shown in FIGS. 3 and 4 where an armof one square member is laid on the opposing arm of the other squaremember respectively. Needless to say, the arms of the first squaremember 15a may be laid on the second square member 15b if desired (notshown).

Although the circular opening 12 is formed in the base plate 11 in theforegoing embodiment, it may be replaced by a circle which is simplydrawn on the base plate 11. Further, a scale may be provided on theouter frame members of the base plate 11 to serve as a ruler.

What is claimed is:
 1. A trimming square set comprising in combination:abase plate having a circular opening therein; a first square memberhaving inner edges set at right angles to each other and pivotallysupported on the base plate by a pin member located at a positionproximate to the peripheral edge of the circular opening of said baseplate, at a point proximate to an intersecting point of said inneredges; a slide plate being slidingly movable on said base plate in adirection parallel with an imaginary line passing through the centers ofsaid pin member and circular opening and provided with a semi-circularnotch congruently with the peripheral edge of said circular opening ofsaid base plate; and a second square member having inner edges set atright angles to each other and pivotally supported on said slide plateby a second pin member located on said imaginary line and in a positionproximate to the peripheral edge of said semi-circular notch, at a pointproximal to the intersecting point of the inner edges thereof.
 2. Thetrimming square set of claim 1, wherein said base plate is provided witha scale of length-to-width ratio of the rectangle formed by inner edgesof said first and second square members.
 3. The trimming square set ofclaim 2, wherein said circular opening of said base plate is providedwith a scale of length-to-width ratio along the peripheral edge thereof.4. The trimming square set of claim 2, wherein said semi-circular notchof said slide plate is provided with a scale of length-to-width ratioalong the peripheral edge thereof.
 5. The trimming square set of claims1, 2, 3 or 4, wherein said base plate is provided with a scale of arealreduction ratio on part of outer frames thereof, indicating the arealreduction ratio of the rectangle formed by inner edges of said first andsecond square members.
 6. The trimming square set of claim 5, whereinsaid scale of areal reduction ratio is provided with outer frameportions along the longer sides of said base plate.